Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:17:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();i++) ^ user.cpp: In function ‘void Update(int, int)’: user.cpp:24:10: warning: statement has no effect [-Wunused-value] for(x;x<=n;x=x+(x&(-x))) ^ user.cpp: In function ‘int Query(int)’: user.cpp:29:10: warning: statement has no effect [-Wunused-value] for(x;x>0;x=x-(x&(-x))) ^ user.cpp: In function ‘int main()’: user.cpp:54:13: warning: unused variable ‘q’ [-Wunused-variable] int i,x,q,m,y; ^ user.cpp: In function ‘void read(int&)’: user.cpp:38:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,DIM,stdin); ^ user.cpp:46:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,DIM,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:52:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in","r",stdin); ^ user.cpp:53:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out","w",stdout); ^ user.cpp:55:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,DIM,stdin); ^